In the field of producing medical images, a silver halide photographic sensitized material has been employed, meanwhile, a silver salt photothermographic dry imaging material which is a recording medium regarding no need to conduct processes of a developing step, a fixing step and a washing step, is proposed.
In patent document 1, patent document 2 and non-patent document 1, identified in a following paragraph, thermo-developable photographic sensitized materials to form photographic images using a thermo-development method are disclosed. The thermo-developable recording media based on this method are expected to be applied in various fields, due to no discharge of a waste material such as a separate sheet, and the ease of forming images using only a heating treatment.
Further, this recording media produces images by processing employing a thermo-development apparatus with a laser light-source. However, the recording media needs to be stably transported under various conditions, and there exists the possibility of generation of static electricity which may cause defects.
The generation of electrostatic charges varies based on the exterior environment, seasonal variations, weather, ambient environment where the apparatus is placed, and ambient conditions where the image recording materials is placed, thus, an electrostatic charge control technology, so-called anti-static technology, is required which is effective under various conditions where the image recording materials are employed.
As electrostatic charge control technology, a technology is known that decreases the amount of separation electrostatic charge generated by contact and separation with certain materials, so-called triboelectric series adjusting technology. Another technology is known using a surface active agent containing a long chain perfluoroalkyl group, a so-called fluorinated surface active agent. However, a fluorinated surface active agent tends to transfer and buildup on the conveyance system in the apparatus, due to its low molecular weight. Therefore, there have been problems with accumulation and transfer of a fluorinated surface active agent on the sheet feeding rollers, and staining of image recording media and transfer failure due to slippage.
In patent document 3, as an antistatic technology of a photographic element is a proposal of a photographic element which contains a polyurethane having a tensile elongation to break of at least 50% and a Young's modulus at 2% elongation of at least 344,737 kPa, a copolymer composed of repeating unit of A and B wherein A comprises a fluorine containing acrylate or a fluorine containing methacrylate monomer and B comprises an ethylenically unsaturated monomer containing groups which can be hydrated and an electrically conductive agent.
The copolymer used in that invention has drawbacks such as adhesion onto the high temperature roller during heat development due to the lowered Tg, in turn due to the long length of a perfluoroalkyl chain of the used polymer containing fluorine, the tendency of adhesion onto the sheet feeding rollers due to high polar characteristics, becoming sticky at high humidity, and being difficult to dissolve when the coating solvent is an organic solvent.
The technologies related to the present invention are described in the following documents.
Patent document 1=U.S. Pat. No. 3,152,904
Patent document 2=U.S. Pat. No. 3,457,075
Patent document 3=JP-A 2000-284420 (hereinafter, the term JP-A refers to Japanese Patent Application Publication)
Non-patent document 1=“Thermally Processed Silver System” (Imaging Processes and Materials), Neblette's 8th edition, edited by J. M. Sturge, V. Walworth, and A. Shepp, 2nd paragraph, (1969).